In diagnosis and treatment using X-rays, a technique of reducing the exposure doses of an object and operator while maintaining the qualities of the diagnosis and treatment is very important, and has been vigorously studied and developed all over the world. The merits of reducing exposure doses are to lead to the suppression of the incidence of cancer and the like and the suppression of the occurrence of cataract and the like.
For example, at the time of treatment of arrhythmia, a technique called X-ray fluoroscopy is used. X-ray fluoroscopy is a technique of continuously displaying, in real time, (moving image display) X-ray images obtained by continuously applying X-rays. The operator performs a procedure by using a device such as a catheter while checking such a moving image. In such a procedure, X-ray irradiation is sometimes continuously performed for several hours, and hence it is required to reduce the exposure doses of the object and operator in this procedure.
As a technique of suppressing exposure doses, for example, there is available a technique of performing X-ray fluoroscopy by irradiating only a region of interest (to be referred to as an ROI hereinafter) in an X-ray fluoroscopy range. In this technique, for example, the operator changes an ROI by operating a switch such as a foot switch. That is, the operator performs the above control during a procedure by some kind of operation which is not directly relevant to the procedure.
A problem to be solved by the present invention is to provide an X-ray diagnostic apparatus which reduces the exposure dose of an object without making the operator actively conscious of a reduction in exposure dose.